Sandblast nozzle



Patented Mar. 8, 1938 SANDBLAST NOZZHJE August Hellmann,Berlin-Charlottenburg,

Germany Application April 24, 1935, Serial No. 17,938 lin Germany April25, lg3d 3 Claims.

Sand blast nozzles having a hard metal insertion are known, wherein thehard metal insertion is hard soldered to an external iron jacket. As thehard metal insertion is very sensitive to shocks or sudden strains owingto the brittle nature of the hard metal, it has already been proposed tosub-divide the insertion into individual anular sections, which mayeasily be replaced when damaged. A further object of the hard solderingis to ensure that the hard metal insertion cracks less easily, while, inthe event of parts cracking in spite of this precaution, such partsmight possibly be held fast to the iron jacket.

The hitherto known arrangements display very great drawbacks inpractice, so that a general use of hard metal for sand blast nozzles isstill not practicable. 'Ihe high wear and tear of hard metal throughcracking prevents introduction of hard metal in sand blast nozzles.

The present invention relates to the securing of hard metal insertionsto an iron jacket. According to the invention a space is providedbetween the hard metal insertion and the iron Y jacket, which .is lledwith rubber for the purpose of securing the hard metal insertion. Withthis arrangement, theI hard metal insertion re, quires considerably lessor no heating during the securing so that the occurrence ofnon-permissible annular strains in the inserted body is preventedimmediately upon manufacture. The layer of rubber between the insertedbody and the iron jacket is also intended to absorb shocks and expansionstrains, whereby the cracking of the hard metal body, which is sofrequently observed in the case of hard soldered nozzles, is practicallyobviated.

A very advantageous constructional form of the invention resides in theprovision of a layer of rubber between the hard metal insertion andtheiron jacket, the arrangement being such that the hard metal insertionand the -iron jacket may be rmly connected with the rubber layer byvulcanization. The securing may also be efiected by inserting a rubberjacket ir the iron (ci. en -n) jacket, and attaching the hard metalinsertion by pressing in (forced fit). The latter method of attachmentrenders possible a convenient replacement-of the hard metal bodies. Thespace between the inserted body and the iron jacket may be of any form.

Two constructional forms of the invention are illustrated by way ofexample in the accompany- -ing drawing, wherein Figures 1 andy 2 are-longitudinal sections respectively of the two forms of sand blastnozzle.

In the drawing, l designates the iron jacket; 2 and 3 the hard metalparts, and 4 a layer of rubber. The hard metal insertion may alsoconsist of only a single part instead of two or more parts.

The term hard metal in the specification comprises all known sinteredhard metal carbides for instance the carbides of tungsten,

' molybdenum, titanium, tantalum, vanadium,

boron, silicon with or without metallic binders such as iron, cobalt,nickel or tungsten or molybdenum and includes further all cast hardmetals which are commerciallyl known under the registered trade-markStellite and High speed steel which contains tungsten and cobalt.

Having now particularly described and ascertained the nature of my saidinventionand in what manner the same is to beperformed, I declare thatwhat I claim iszl. A sand blast nozzle having a jacket and a hard linerconcentrically arranged therein, characterized by the fact that theliner is attached in the jacket by a layer of soft rubberarrangedbetween said hard liner and said jacket. i

2. A sand blast nozzle ,according to claim 1 characterized by the factthat the jacket and said hard liner are firmly connected with saidrubber layer by vulcanization.

3. A sand blast nozzle having a jacket and a hard line-r concentricallyarranged therein, characterized by the fact that the hard liner isattached in the rubber layer by frictional contact.

AUGUST Rani/mini.v

lo v

